document.addEventListener('DOMContentLoaded', function() {
  // 回到顶部按钮
  const backToTopButton = document.getElementById('back-to-top');

  window.addEventListener('scroll', function() {
    if (window.pageYOffset > 300) {
      backToTopButton.style.display = 'block';
    } else {
      backToTopButton.style.display = 'none';
    }
  });

  backToTopButton.addEventListener('click', function(e) {
    e.preventDefault();
    window.scrollTo({
      top: 0,
      behavior: 'smooth'
    });
  });

  // 评论表单提交
  const commentForm = document.getElementById('comment-form');
  if (commentForm) {
    commentForm.addEventListener('submit', function(e) {
      e.preventDefault();

      const name = document.getElementById('name').value;
      const commentText = document.getElementById('comment').value;

      if (name && commentText) {
        const commentsList = document.getElementById('comments-list');
        const now = new Date();
        const dateStr = now.toLocaleDateString('zh-CN');

        const newComment = document.createElement('div');
        newComment.className = 'comment';
        newComment.innerHTML = `
          <div class="comment-author">
            <img src="https://via.placeholder.com/50" alt="用户头像">
            <span>${name}</span>
          </div>
          <div class="comment-content">
            <p>${commentText}</p>
            <div class="comment-meta">${dateStr}</div>
          </div>
        `;

        commentsList.appendChild(newComment);

        // 清空表单
        commentForm.reset();

        // 滚动到新评论
        newComment.scrollIntoView({ behavior: 'smooth' });
      }
    });
  }

  // 联系表单提交
  const contactForm = document.querySelector('.contact-form');
  if (contactForm) {
    contactForm.addEventListener('submit', function(e) {
      e.preventDefault();

      const name = contactForm.querySelector('input[type="text"]').value;
      const email = contactForm.querySelector('input[type="email"]').value;
      const message = contactForm.querySelector('textarea').value;

      if (name && email && message) {
        alert(`感谢您的留言，${name}！我们会尽快回复您。`);
        contactForm.reset();
      } else {
        alert('请填写所有必填字段！');
      }
    });
  }

  // 订阅表单提交
  const subscribeForm = document.querySelector('.subscribe-form');
  if (subscribeForm) {
    subscribeForm.addEventListener('submit', function(e) {
      e.preventDefault();

      const email = subscribeForm.querySelector('input[type="email"]').value;

      if (email) {
        alert(`感谢订阅！我们已将确认邮件发送至 ${email}`);
        subscribeForm.reset();
      } else {
        alert('请输入有效的邮箱地址！');
      }
    });
  }
});